Hantarex MTC 9110 instant glare

[myazgan]

Hello to everyone.
I noticed flashes on my hantarex mtc 9110 monitor, which are more visible when approaching the screen.
the voltages in the tube seem to be bouncing.
What do you think could be the reason? Should I be afraid of this situation?

https://www.youtube.com/shorts/EvEF_RArXTQ

[myazgan]

up

[lilshawn]

you sure it's not just your eye pupils adjusting for the light of the monitor?

place a static image on the screen and see if it's doing it.

not sure what you mean by "flashes"... periods of bright white is what i think of when someone says "flash" could be a problem with the signal going into the tube not being even... could also be a voltage or blanking problem. hard to tell from your description.

the chassis B+ voltage will bounce around as the screen image changes... dark images or black will show a high voltage... bright screens and white will show lower voltages. (as the tube consumes power to make the image) again, place a static non moving image on the screen and see if the voltage changes. it should only vary a tiny bit, not more than say... a 0.2 of a volt? its going to depend on lots of things. if it's still wildly swinging around even with a static non moving image, i'd look into the main B+ capacitors and replacing them if you haven't already.

[myazgan]

you sure it's not just your eye pupils adjusting for the light of the monitor?

place a static image on the screen and see if it's doing it.

not sure what you mean by "flashes"... periods of bright white is what i think of when someone says "flash" could be a problem with the signal going into the tube not being even... could also be a voltage or blanking problem. hard to tell from your description.

the chassis B+ voltage will bounce around as the screen image changes... dark images or black will show a high voltage... bright screens and white will show lower voltages. (as the tube consumes power to make the image) again, place a static non moving image on the screen and see if the voltage changes. it should only vary a tiny bit, not more than say... a 0.2 of a volt? its going to depend on lots of things. if it's still wildly swinging around even with a static non moving image, i'd look into the main B+ capacitors and replacing them if you haven't already.

Thank you for your comment.
In the video I have attached, when you look at the left side of the letter p, it is very noticeable. I can describe it as a flash or jump.

Even if I give a fixed image (test screen), the same jumps or explosions continue.

I didn't change the cap but it should be a last resort for me

[lilshawn]

ok, i see.... it seems there is a tiny bit of synchronization jittering going on, but I'm not really sure where you might start looking. not sure if this is an original pacman  game board or if it's an xxx-in-1 type deal, but it could be your game board having a variance in timing or something as it seems to be doing it in a vertical direction to the monitors scan direction. maybe a power supply introducing noise? could just be a bad ground somewhere give the video cable a wiggle and clean up the board contacts and make sure everything has a good connection.

it could be something in the monitor. there is a timing capacitor for the vertical deflection circuit. it's gonna be a small (like 100uF 35v (C9?) near the vertical deflection IC) cap that's responsible for the main timing ... it's constant charge/discharge being the "heartbeat" of the timing for the vertical circuit to go to the next line. if it's starts getting old and flakey, it can cause jitteriness... it's usually much more noticeable than this and you end up with weird overlapping and foldunder and stuff so it could just be marginal.

it's not something to really worry about. i mean it's not doing too much... just a little annoying if you stare at it looking for it. if you have a screenful of stuff moving around and you are playing it, you aren't going to notice it.

if it's really getting to you and you really need to do something about it... if you have another monitor or another gameboard/power supply you can try... see if it's coming out of the board like that or it's the actual monitor doing it, becasue honestly, it could be either one doing it from what i can see.

if not, and your monitor has never been serviced, maybe start with a cap kit for your monitor and see if it still does it. they are pretty cheap insurance for the future and will make that monitor outlast you... but will also MOSTLY eliminate the monitor as a source of the jitter.

[myazgan]

ok, i see.... it seems there is a tiny bit of synchronization jittering going on, but I'm not really sure where you might start looking. not sure if this is an original pacman  game board or if it's an xxx-in-1 type deal, but it could be your game board having a variance in timing or something as it seems to be doing it in a vertical direction to the monitors scan direction. maybe a power supply introducing noise? could just be a bad ground somewhere give the video cable a wiggle and clean up the board contacts and make sure everything has a good connection.

it could be something in the monitor. there is a timing capacitor for the vertical deflection circuit. it's gonna be a small (like 100uF 35v (C9?) near the vertical deflection IC) cap that's responsible for the main timing ... it's constant charge/discharge being the "heartbeat" of the timing for the vertical circuit to go to the next line. if it's starts getting old and flakey, it can cause jitteriness... it's usually much more noticeable than this and you end up with weird overlapping and foldunder and stuff so it could just be marginal.

it's not something to really worry about. i mean it's not doing too much... just a little annoying if you stare at it looking for it. if you have a screenful of stuff moving around and you are playing it, you aren't going to notice it.

if it's really getting to you and you really need to do something about it... if you have another monitor or another gameboard/power supply you can try... see if it's coming out of the board like that or it's the actual monitor doing it, becasue honestly, it could be either one doing it from what i can see.

if not, and your monitor has never been serviced, maybe start with a cap kit for your monitor and see if it still does it. they are pretty cheap insurance for the future and will make that monitor outlast you... but will also MOSTLY eliminate the monitor as a source of the jitter.

Thank you very much. I tried with other original mvs and pandora box, the problem on the monitor did not change.
not related to the game.
As you said, it can be fixed as a result of cap kit change.

[lilshawn]

yeah, if the monitor has never been serviced, those caps are probably 30 years old now it's on borrowed time. capacitor lifetimes are measured hours, not years. good high quality ones will stay in spec for 5000 hours of use before they start drifting off into the abyss. mainstream commercial ones maybe 3000... which in the grand scheme of things, is't a whole lot. i got machines out on route that i end up dragging in and have to recap every few years cause they are on literally 24/7.